黄河口沉积物固结过程电阻率监测研究

Monitoring of resistivity of sediment during consolidation process in Yellow River mouth

在现代黄河口采集沉积物,通过室内土样真空预压装置使沉积物固结,利用高密度电阻率仪监测沉积物固结过程中电阻率的变化;利用孔隙水压力监测、十字板剪切测试与微型贯入测试等测试手段,实时测定固结沉积物的孔压和不排水抗剪切强及贯入强度的变化;并定期取土样进行常规土工试验和室内固结试验。研究结果表明,黄河口沉积物在固结过程中土体电阻率大小同固结程度密切相关,固结过程中影响黄河口饱和粉土电阻率的主要因素为孔隙率;黄河口饱和粉土的电阻率与土体物理力学指标之间存在良好的相关性,通过电阻率测定可以有效估算土体各项固结指标,本研究为海床沉积物固结过程的原位监测提供了一条新途径。

Laboratory model tests are performed on the silty samples collected from the Yellow River mouth and consolidated in a vacuum device.By use of some test methods such as vane shear tests,micro-penetration tests,pore water piezometer tests and muti-electrode methods,the variation of strength,pore water pressure and resistivity during the consolidation process is timely measured.Routine soil tests and laboratory consolidation tests on silty samples are periodically conducted.It is shown from the test data that the resistivity closely relates with the degree of consolidation,and that the porosity is the main factor to control the resistivity of silty soil in the Yellow River mouth during the consolidation process.The electrical resistivity has a good relationship with the physical and mechanical indexes.Through electrical resistivity measurements,the consolidation indexes of soil are effectively estimated.It provides a new way for in-situ monitoring of marine sediment during the consolidation process.